The shooting stemmed from a fight among some casino visitors, and a Potawatomi spokesman told WISN 12 News that a security officer tried to break it up before the shots were fired.

"As our security officers are instructed to do, she intervened. She was knocked down, incapacitated. She called for backup," Amundson said.

But other security officers were tending to a medical emergency in another part of the casino, leaving casino guests to try to wrestle the gun from the gunman.

"We need to get that gun because there was still two guys on the floor fighting over that gun," said De Von Dent, who confronted the suspect.

"I had to get the gun. I already saw that somebody was shot and that could have been my friend. That could have been anybody. I had to get the gun from him," said Antonio Felder, who confronted the suspect.

They questioned the lack of action by casino security, but the spokesman said the casino believes its security personnel acted appropriately.

"It's not an armed team of security officers. Their job is to identify a threat, keep people away from that threat, move away from the threat and then become witnesses themselves until police backup arrives," Amundson said.

Casino officials told WISN 12 News they are taking the matter very seriously as they re-evaluate their security procedures.

But it does have the popular tribal casino rethinking its safety procedures. Amundson said new steps are being considered to ensure this type of incident won't happen again.

WE ARE FOLLOWING NEW DEVELOPMENTS IN THE SHOOTING ON THE CASINO FLOOR AT POTAWATOMI. A WAUWATOSA MAN IS IN CUSTODY AFTER A WOMAN WAS SHOT IN THE LEG EARLY YESTERDAY. WISN-12 NEWS KENT WAINSCOTT JOINS US, AND KENT, WE'RE GETTING A BETTER PICTURE OF THE MOMENTS THAT LED UP TO THE SHOOTING. IT WAS ABOUT ONE- THIRTY YESTERDAY MORNING WHEN A MAN OPENED FIRE INSIDE THE CASINO - THOUSANDS OF PEOPLE WERE INSIDE THE BUILDING AT THE TIME. AND WE'VE NOW LEARNED THAT A SECURITY OFFICER STEPPED IN TO STOP THE INCIDENT BEFORE THE SHOOTING BEGAN. 1:16 :10 :24 :40-44 :48 AS FIRST RESPONDERS RUSHED TO THE SCENE IN THE EARLY MORNING HOURS OF SUNDAY, THESE CELL PHONE IMAGES SHOW THE PANIC INSIDE AS A MAN OPENED FIRE IN THE CROWDED CASINO. PATRICIA WESLEY - I JUST HEARD PEOPLE RUNNING AND SHOUTING 'SOMEBODY IS SHOOTING. SOMEBODY IS SHOOTING. THE SHOOTING STEMMED FROM A FIGHT AMONG SOME CASINO VISITORS, AND A POTAWATOMI SPOKESMAN TELLS WISN-12 NEWS THAT A SECURITY OFFICRE TRIED TO BREAK IT UP BEFORE THE SHOTS WERE FIRED. RYAN AMUNDSON - AS OUR SECURITY OFFICERS ARE INSTRUCTED TO DO, SHE INTERVENED. SHE WAS KNOCKED DOWN, INCAPACITATED. SHE CALLED FOR BACK-UP. BUT OTHER SECURITY OFFICERS WERE TENDING TO A MEDICAL EMERGENCY IN ANOTHER PART OF THE CASINO - LEAVING CASINO GUESTS TO TRY TO WRESTLE THE GUN FROM THE GUNMAN. DE VON DENT - WE NEED TO GET THAT GUN, BECAUSE THERE WAS STILL TWO GUYS ON THE FLOOR FIGHTING OVER THAT GUN. ANTONIO FELDER - I HAD TO GET THE GUN. I ALREADY SAW THAT SOMEBODY WAS SHOT AND THAT COULD HAVE BEEN MY FRIEND. THAT COULD HAVE BEEN ANYBODY. I HAD TO GET THE GUN FROM HIM. THEY QUESTIONED THE LACK OF ACTION BY CASINO SECURITY - BUT THE SPOKESMAN SAYS THE CASINO BELIEVES THEIR SECURITY PERSONNEL ACTED APPROPRIATELY. RYAN AMUNDSON - IT'S NOT AN ARMED TEAM OF SECURITY OFFICERS. THEIR JOB IS TO IDENTIFY A THREAT, KEEP PEOPLE AWAY FROM THAT THREAT, MOVE AWAY FROM THE THREAT AND THEN BECOME WITNESSES THEMSELVES UNTIL POLICE BACKUP ARRIVES. WE'RE TOLD THE THE VICTIM HAD NON-LIFE THREATENING INJURIES. THE SUSPECT IS IN CUSTODY, LATE THIS AFTERNOON WE LEARNED THE CASE IS NOW IN THE HANDS OF THE DISTRICT ATTORNEY'S OFFICE UNDER REVIEW. NO WORD ON WHEN CHARGES MAY COME. BUT COMING UP AT SIX - WE'LL LOOK AT THE SECURITY CHANGES THAT ARE BEING CONSIDERED HERE AT THE CASINO. CHANGES THAT COULD IMPACT MILLIONS OF VISITORS. LIVE OUTSIDE POTAWATOMI BINGO CASINO, I'M KENT WAINSCOTT WISN-12 NEWS. POTAWATOMI FIRST OPENED IN 19-91. THIS WAS THE FIRST TIME A SHOOTING HAS EVER HAPPENED INSIDE THE CASINO. IT'S GONE THROUGH TWO MAJOR EXPANSIONS AND IS THE MIDDLE OF BUILDING A HOTEL RIGHT NOW. IN 2008, POTAWATOMI TRIPLED ITS SIZE WHEN IT COMPLETED A 240 MILLION DOLLAR EXPANSION.